In many electrical and electronic systems, it may be desirable to measure a capacitance within a circuit in order to take action responsive to the measured capacitance. One type of apparatus for measuring capacitance is known as a capacitance-to-digital converter, or “CDC,” which is capable of measuring a capacitance and generating a digital output signal indicative of a magnitude of the measured capacitance.
Many traditional and existing CDCs possess significant drawbacks and disadvantages. For example, existing CDCs are often implemented using an open-loop capacitance-to-voltage converter (CVC) followed by an anti-aliasing filter and a discrete-time analog-to-digital converter (ADC). One disadvantage associated with the use of an open-loop CVC is that open-loop CVCs often suffer from signal distortion. In addition, one disadvantage in using a discrete-time ADC is that it requires the use of the anti-aliasing filter, which requires physical area within a circuit and consumes significant power during operation.